Company wants lower groundwater contamination standards

GRANTS, N.M. — A company wants New Mexico to set a lower standard for groundwater contamination at the site of a uranium mine it has spent more than a decade cleaning up.

United Nuclear Corp. operated the St. Anthony Mine from 1975-1981 and started cleaning up the site in 2004. The company is asking state regulators to approve a variance thousands of times above current groundwater standards, the Gallup Independent reported.

The New Mexico Water Quality Control Commission scheduled a public hearing for next month and says monitoring wells continue to show groundwater being affected by levels of contaminants.

The land consists of two open pits and one underground mine. The company wants to backfill the large open pit so it can proceed with cleanup.

That pit currently captures groundwater in the Jackpile sandstone aquifer through a cone of depression that has developed in response to evaporation of pit water, according to the report.

The water in the pit, as well as water in monitoring wells outside the large open pit, already exceeds state water quality standards, according to the report.

The New Mexico Environment Department is recommending the commission accept the alternate limits, saying a full cleanup is not feasible under the current standards.

"It is not technologically feasible to remove the rock that contains the groundwater," the state said, because it also would require removing the groundwater as well, and would be "very costly and have a negative environmental impact."

The site is located in a sparsely populated rural area and land owners indicated there are no plans for future consumption of the groundwater, according to the report.

The contaminants of concern are uranium, radon-226 and 228, boron, fluoride, sulfate, chloride and total dissolved solids.